The SureStep EZ Split Cup Urine Test is an immunoassay that functions on the principle of competitive binding. In this method, drugs that may be present in the urine specimen compete with their respective drug conjugate for binding sites with their specific antibody.
During the SureStep EZ Split Cup Urine Testing, a portion of the urine sample moves upward via capillary action. If a drug is present in the urine sample below its cut-off concentration, it will not saturate the binding site of its specific antibody. Consequently, the antibody will react with the drug-protein conjugate, causing a visible coloured line to appear in the corresponding drug strip’s test line region. However, if the drug concentration in the urine sample is above the cut-off concentration, it will saturate all the binding sites of the antibody, and no coloured line will appear in the test line region.
A non-negative urine sample will not generate a coloured line in the specific test line region of the strip due to drug competition. On the other hand, a drug-negative urine sample will generate a line in the test line region because of the absence of drug competition. To ensure proper procedural controls, a coloured line will always appear in the control line region, indicating that the appropriate volume of the specimen has been added, and membrane wicking has taken place.
